feat(frontend): TypeScript-Monorepo mit Terminal-UI für Effigenix ERP

Monorepo-Setup (pnpm workspaces) mit vier shared Packages und einer TUI-App:

Shared Packages:
- @effigenix/types: TypeScript-DTOs (UserDTO, RoleDTO, AuthDTO, Enums)
- @effigenix/config: API-Konfiguration und Shared Constants
- @effigenix/validation: Zod-Schemas für Username, E-Mail und Passwort
- @effigenix/api-client: axios-Client mit JWT-Handling (proaktiver + reaktiver
  Token-Refresh), AuthInterceptor, ErrorInterceptor, Resources für auth/users/roles

TUI (apps/cli, Ink 5 / React):
- Authentication: Login/Logout, Session-Restore beim Start, JWT-Refresh
- User Management: Liste, Anlage (Zod-Inline-Validation), Detailansicht,
  Passwort ändern, Sperren/Entsperren mit ConfirmDialog
- Role Management: Liste, Detailansicht, Zuweisen/Entfernen per RoleSelectList (↑↓)
- UX: SuccessDisplay (Auto-Dismiss 3 s), ConfirmDialog (J/N),
  FormInput mit Inline-Fehlern, StatusBar mit API-URL
- Layout: Fullscreen-Modus (alternate screen buffer), Header mit eingeloggtem User
- Tests: vitest + ink-testing-library (15 Tests)

frontend/apps/cli/src/App.tsx

@@ -0,0 +1,64 @@
+import React, { useEffect } from 'react';
+import { Box } from 'ink';
+import { AuthProvider, useAuth } from './state/auth-context.js';
+import { NavigationProvider, useNavigation } from './state/navigation-context.js';
+import { LoginScreen } from './components/auth/LoginScreen.js';
+import { MainMenu } from './components/MainMenu.js';
+import { MainLayout } from './components/layout/MainLayout.js';
+import { LoadingSpinner } from './components/shared/LoadingSpinner.js';
+import { UserListScreen } from './components/users/UserListScreen.js';
+import { UserCreateScreen } from './components/users/UserCreateScreen.js';
+import { UserDetailScreen } from './components/users/UserDetailScreen.js';
+import { ChangePasswordScreen } from './components/users/ChangePasswordScreen.js';
+import { RoleListScreen } from './components/roles/RoleListScreen.js';
+import { RoleDetailScreen } from './components/roles/RoleDetailScreen.js';
+
+function ScreenRouter() {
+  const { isAuthenticated, loading } = useAuth();
+  const { current, navigate } = useNavigation();
+
+  // Redirect zu main-menu nach erfolgreichem Login
+  useEffect(() => {
+    if (isAuthenticated && current === 'login') {
+      navigate('main-menu');
+    }
+  }, [isAuthenticated, current, navigate]);
+
+  if (loading) {
+    return (
+      <Box alignItems="center" justifyContent="center" paddingY={4}>
+        <LoadingSpinner label="Initialisiere..." />
+      </Box>
+    );
+  }
+
+  if (!isAuthenticated) {
+    return (
+      <MainLayout showHeader={false}>
+        <LoginScreen />
+      </MainLayout>
+    );
+  }
+
+  return (
+    <MainLayout>
+      {current === 'main-menu' && <MainMenu />}
+      {current === 'user-list' && <UserListScreen />}
+      {current === 'user-create' && <UserCreateScreen />}
+      {current === 'user-detail' && <UserDetailScreen />}
+      {current === 'change-password' && <ChangePasswordScreen />}
+      {current === 'role-list' && <RoleListScreen />}
+      {current === 'role-detail' && <RoleDetailScreen />}
+    </MainLayout>
+  );
+}
+
+export function App() {
+  return (
+    <NavigationProvider initialScreen="login">
+      <AuthProvider>
+        <ScreenRouter />
+      </AuthProvider>
+    </NavigationProvider>
+  );
+}